Portable infusion pump of the skin patch type with spiral collapsible reservoir

Abstract

An ambulatory pump comprising a reservoir ( 1 ) for holding the fluid to be pumped and having an outlet ( 7 ) through which fluid is expelled in use; a closure ( 8 ) device movable relative to the reservoir; and an actuator ( 14 ) for moving the closure device relative to the reservoir, wherein the reservoir is arranged in a spiral pattern.

1. An ambulatory pump for dispensing fluid to be pumped through a transcutaneous cannula comprising:
 a reservoir comprising a relatively long length of flexible tubing arranged in a spiral pattern for holding the fluid to be pumped and having an outlet through which fluid is expelled in use; 
 a closure device disposed external to the flexible tubing and engaging an exterior surface thereof, said closure device being discretely movable relative to the flexible tubing forming the reservoir for crushing the reservoir; and 
 an actuator for moving the closure device incrementally relative to the reservoir. 
 
     
     
       2. A pump according to  claim 1 , wherein the closure device is configured to contact the outside of the reservoir such that movement of the closure device towards the outlet of the reservoir crushes part of the reservoir, thereby causing fluid to be expelled from the reservoir. 
     
     
       3. A pump according to  claim 1 , wherein the closure device experiences a smaller frictional force when moving towards rather than away from the outlet. 
     
     
       4. A pump according to  claim 1 , wherein the closure device is configured such that, in use, it is only movable towards the fluid to expel fluid from the reservoir. 
     
     
       5. A pump according to  claim 1 , wherein the closure device further comprises a leg extending rearwardly from the closure such that the leg contacts the outer surface of the reservoir. 
     
     
       6. A pump according to  claim 1 , further comprising a ratchet mechanism which engages with the closure device to permit travel only towards the outlet. 
     
     
       7. A pump according to  claim 1 , wherein the reservoir comprises a flexible tube. 
     
     
       8. A pump according to  claim 7 , wherein the reservoir has an aspect ratio of between 100 and 10000. 
     
     
       9. A pump according to  claim 1 , wherein the spiral is Archimedean. 
     
     
       10. A pump according to  claim 1 , wherein the reservoir is formed from a non-resilient material. 
     
     
       11. A pump according to  claim 1 , wherein the actuator includes a shape memory alloy element for causing the closure device to move relative to the reservoir and thereby expel fluid from the reservoir. 
     
     
       12. A pump according to  claim 1 , wherein the actuator is oscillatory. 
     
     
       13. A pump according to  claim 12 , wherein the rotational movement of the oscillatory actuator is limited such that the closure element can only move a predetermined amount for any single actuation. 
     
     
       14. A pump according to  claim 12 , wherein the oscillatory actuator returns to its rest position by means of a biasing means. 
     
     
       15. A pump according to  claim 14 , wherein the biasing means includes at least one of the following: a spring or a shape memory alloy wire.